An unbalanced electronic gizmo is hard to make balanced. You could 'fake' balance it with some cheap parts, but it would be no better (or it could be worse) than the original unbalanced unit.
A true blanced device has TWO equal parts mirrored around a common ground. (you would need twice as many parts, well designed to function as a balanced crossover)
I would say it is not a good idea to try and 'force' the crossover you now have into a usable configuration. It can be done, but it will be a juryrigged, compromised thing.
Biamping is only sometimes better, and I would say the experiment can be done, but it would be a waste of time with the current crossover.
Perhaps someday you can find one that is a true balanced design
Be happy with what you have!!